This invention relates to a feeding mechanism whereby shuttles in an automatic wave or progressive shed loom are positively fed into the spiral groove between nose-like projections of driving hooks on a weaving cylinder of an automatic wave shed loom. The apparatus of the present invention is directed to a positive insertion of the shuttles by means of a conveyor and driving pins into the spiral grooves between the nose-type projections of the driving hooks.
Automatic wave shed looms have been known. In these automatic wave shed looms, the movement of the shuttle into and out of the progressive sheds is effected by means for beating up the weft threads. This means has recesses therein which are responsible for releasing the temporarily guided shuttles. When the shuttle enters the sheds, it is released immediately above the groove of the beating up means formed by the driving hooks. After the shuttles have passed through the sheds formed, they are pushed by driving hooks of the beating up means into the recesses of the return drum. As soon as the return drum has performed a revolution up to the return device, the shuttles held in the recesses are released by loosening a pawl. The return device moves the shuttles into the recesses of the feed drum and after winding with weft thread of predetermined length, the shuttles are fed to the beating up means as described above and the cycle is closed.
It is already been proposed to effect the feeding of the shuttles into the sheds formed by means of a conveyor shaft with a rectangular spiral and a guide partly embracing the latter. The guide has recesses through which the shuttles can be fed.
While such a mechanism can work, it suffers from the disadvantage that in the use of the pawls, a specific control is required. If the pawl is not released at the exact, correct moment of time, the driving hooks can be destroyed and the shuttles can be damaged. The free fall movement can lead to the canting of the shuttle which can likewise cause breaks. These problems can only be eliminated by complicated and expensive apparatus and by extreme care in the use thereof.
The proposed feeding method for shuttles employing a revolving conveyor worm suffers from the disadvantage that it does not positively push the shuttles completely into the groove of the beating up means formed by the nose-type projections. This is due to the fact that the conveyor worm requires a separate support between the beating up means and the end of the conveyor worm. This support in turn requires a certain space which forms practically an interval between the beating up means and the conveyor worm. In this interval, there is a complete absence of a pushing action on the shuttles. At the high revolving speeds, the shuttles are pushed into the groove of the beating up means only by their inherent kinetic energy. The end position of the shuttles in the groove can thus not be exactly predetermined. There may be shocks when the shuttles slide farther to the front and the nose-type projections of the driving hooks follow somewhat later. Finally, an exactly predetermined positon of the shuttle of the head of the beating up means is necessary to insure a positive grip of the freely protruding weft end.
It, therefore, became desirable to provide a feeding apparatus for an automatic progressive shed loom whereby the shuttle would be positively fed into the spiral grooves defined by the nose-like projections of the driving hooks of a beating up means. Moreover, it became desirable to provide such an apparatus which would avoid shocks and breaks in the feeding of the shuttles into the beating up means. It became particularly desirable to provide for such an apparatus whereby the shuttle could be positively fed into the spiral grooves by a simple conveyor means which did not require the elaborate construction which apparatus avoids creation of an interval between a beating up means and a conveyor.